Explain what a pseudo-noble-gas electron configuration is. Give examples of ions that have this type of configuration.

Any element that would need to rid itself of three or more electrons to achieve a noble gas configuration (a transition metal), is extremely unlikely to do so. Instead, an element will lose its incomplete sublevel (a lone 4s, 5s, etc. electron) that results with 18 electrons in the highest occupied energy level, and all of its orbitals filled. It now has a pseudo noble-gas electron configuration. Example Zn2+, Cd2 + ions